Japanese Laid Open Patent No. H06-146867 discloses a combustion engine having a fresh air supplying device capable of supplying fresh air upstream of an exhaust purification catalyst, which is arranged in an exhaust passage, and of controlling the combustion air-fuel ratio in a combustion chamber so as to be rich when warming-up of the catalyst is required, and at the same time, operating a fresh air supplying device to supply fresh air to the exhaust passage.